icmp.c

ATmega103、ATmega128做的开发板web server源码

/******************************************************************
* icmp.c: Internet Control Messaging Protocol
* 
* Copyright (c) 2001 Atmel Corporation.
* All Rights Reserved.
*
* You are autorized to use, copy and distribute this software only at 
* a single site (the term "site" meaning a single company location). 
* This copyright notice must be included in any copy, modification 
* or portion of this software merged into another program.
* 
* This software is licenced solely for use with Atmel AVR micro 
* controller family. The software may not be modified to execute on 
* any other microcontroller architectures
*
* This software is provided "as is"; Without warranties either express
* or implied, including any warranty regarding merchantability, 
* fitness for a particular purpose or noninfringement. 
*
* In no event shall Atmel or its suppliers be liable for any special, 
* indirect,incidential or concequential damages resulting from the 
* use or inability to use this software.
*
* Revision history:
*
* January 17, 2001:   Version 1.0   Created by JB
* July 13, 2001		  Version 1.2     JB
* 					- Changed to IAR compiler V2.25
*					- Renamed flash file functions to avoid conflict with 
*					  standard file I/O names	
*					- Bug fixes in HTTP
*					- Speed optimization in TCP 
*
*
*******************************************************************/

#include "icmp.h"
#include "ip.h"
#include "main.h"
#include <iom103.h>

extern unsigned int frame[FRAME_SIZE];

/*receiving a ICMP message. If this is a echo request, reply with a echo reply.*/
void receiveICMP( unsigned int *frame, int length, unsigned int ip0, unsigned int ip1) 
{
  unsigned int *frameptr = &frame[ICMP_TYPE];
  
  if ( ((*frameptr>>8)&0xff) == 8)  
  {
    /* Echo and Echo Reply Message */
    *frameptr++ = 0;
    *frameptr = 0;
    *frameptr = checksum(&frame[ICMP_TYPE], length);
    transmitIP(length, ip0, ip1,1);
  }
}